The present invention relates to an encapsulated switching system for longitudinal coupling of bus bars of multi-phase bus bar systems installed in an encapsulated switch housing having a front section, a plurality of covers, inner partitions separating portions of the bus bar systems from one another, and a plurality of coupling fields for coupling together sections of the bus bars. In a known system of this type, at least two bus bars of a bus bar system have axes arranged in a plane which is at least approximately parallel to the nearest cover. Each bus bar has a first end section and a second end section. The first and second end sections of respective bus bars are arranged in different coupling fields. Each coupling field accommodates a first disconnect switch and a coupling switch along with a respective one of the first end sections of the bus bars. A second disconnect switch is provided in each coupling field connected at one end to a respective one of the coupling switches Coupling lines are provided between another end of a respective one of the second disconnect switches and a connecting point at a respective one of the second bus bar end sections, the coupling lines being connected by way of a terminal that is brought through, in an insulated manner, either a first partition surrounding the respective second bus bar end section or one of the housing covers. The coupling switches have poles arranged in a straight line or slightly offset with respect to the front of the switch housing.
The publication entitled, "Stahlblechgeschotte, SF.sub.6 -insulierte Schaltanlagen Typenreihe ZV2" [Steel Sheet Protected, SF.sub.6 Insulated Switching Systems, Series ZV2], Calor Emag (publication 13/76/H) discloses at page 7 a double bus bar system for which longitudinal coupling with power switches for each one of the two systems corresponds to the features of the encapsulated switching system described above.
The prior art switching system includes two superpose bus bar systems which are installed in the lower region of a switching system. Each bus bar system is connected with a power switch and with a cable terminal by way of a three-way switch. In an upper portion of each outgoing field, an upper terminal of the power switch may be brought to the cable terminal by way of current converters. Each one of the two coupling fields includes a respective first bus bar end section, an associated first three-way switch, a coupling switch in the form of a power switch and a passage for a coupling line, which couples the first bus bar end section with a second bus bar end section, disposed outside of the encapsulation. In an upper portion of the coupling fields, current and voltage converters (transformers) also be disposed. Next to the two coupling fields, there is a supplemental field in which are accommodated second bus bar end sections for both bus bar systems, each provided with a three-way switch. By way of terminals, the three-way switches are connected with coupling lines which are brought from the coupling fields to the supplemental field in two superposed planes, since the coupling lines of the individual phases of the two systems intersect one another. Otherwise, the supplemental field has no active components.
Thus, in order to longitudinally couple a two bus bar system, the prior art switching system requires, in addition to a coupling field for each bus bar system, a third field as a supplemental field in which the two second bus bar end sections and the associated three-way switches are accommodated. Moreover, the height of the switching system is increased by the coupling lines for both systems placed on top of it. Expansion of the prior art switching system to a triple bus bar system would require even more space in the building housing the switching system with respect to longitudinal coupling since the three coupling fields would require the accommodation of two supplemental fields, and three planes with coupling lines would have to be accommodated in the height direction.
The BBC Switching Systems Handbook, 8th Edition, shows at page 414 a switching diagram for longitudinal and transverse coupling for a triple bus bar system. In this disclosure, each system includes a sectionalizing switch which can be bridged by a coupling switch. Such a system is instrument intensive and space consuming and is thus not suitable for an encapsulated switching system, and in particular not for switching systems insulated with compressed gas.